1. Field of the Invention
The present invention relates generally to tissue receiving systems and more particularly to a tissue filtering and retrieval system that permits selective opening of a tissue filter.
2. Description of the Related Art
Tissue filters, especially for biopsy systems, are used to collect tissue samples taken from a patient during a medical procedure, such as a biopsy. In known systems, the tissue filter is generally placed within a filter canister and then tissue is drawn into the filter by a vacuum source connected to the canister. The tissue is then separated from the fluids that may also be drawn into the canister by the vacuum. The tissue sample may then be retrieved from the filter for analysis. In practice, the tissue filter may be used with a tissue resecting device such as a breast biopsy device. In this case, the tissue is resected from the patient, collected in the filter, and removed from the filter for subsequent pathological evaluation.
Current tissue collection systems are difficult to use and do not provide for easy removal of the resected tissue, or core. Many systems incorporate a cylindrical filter, positioned inside a collection canister that separates the tissues from the fluids and captures the resected tissue. After collection, a retrieval element, or scoop, may be used to “pop out” the resected tissue from the cylindrical filter. In many cases, the tissue core may be difficult to eject using the retrieval element when the filter is full. If the tissue core is successfully ejected, there may still be fine tissue surrounding the filter than was not removed by the retrieval element. Further, when there are fine tissues surrounding the filter, the retrieval element may not be able to lift or scrape the fine tissue from the filter wall in subsequent retrieval efforts. In this case, more samples may need to be taken or the resulting tissues collected may be damaged during retrieval. Additionally, the tissue collection systems using retrieval elements are expensive to manufacture due to the additional parts that must be manufactured and packaged with the filter.
Accordingly, an improved tissue filter is required that facilitates simple, easy, and reliable retrieval of tissue from the filter. The new filter should provide comfortable access to the resected tissue, as well as allow for retrieval of fine tissues that may be stuck directly to the filter wall. Additionally, the improved tissue filter should be less costly to manufacture than current filter designs.